The National Weather Service has issued a winter storm watch for Winnebago, Boone, McHenry, Ogle, Lee and De Kalb counties. Snow is expected to begin falling Thursday morning or possibly Wednesday night in those counties and could accumulate up to six inches -- or even more, according to the watch.

The storm watch takes effect Thursday morning and will remain in effect until that evening.

Chicago's snowfall will arrive Thursday afternoon and is not expected to accumulate as much as it will in the north and western suburbs, said Amy Seeley, a meteorologist with the National Weather Service in Romeoville.